JPH01122506A - Heat-resistant electric wire or cable - Google Patents

Abstract

PURPOSE:To obtain an electric wire or a cable with the electrical insulation property, heat resistance deformation property, chemical resistance, and flame resistance by covering a specific liquid crystal polymer insulating layer on the surface of a conductor. CONSTITUTION:Total aromatic polyester liquid crystal polymer reacted with p, p'-biphenyl, p-hydroxybenzoic acid, and terephtalic acid is provided on the surface of a conductor as an insulating cover layer. A nonflammable tape is wound between the conductor and the liquid crystal polymer insulating layer to provide a separator layer. A tape made of metal, glass, glass mica or ceramic, or a tape made of polyimide, polybismaleimide triazine, polyaminobismaleimide or polyamideimide hardening resin, a tape made of thermoplastic aromatic polyester liquid crystal polymer, or a tape made of thermoplastic resin with the melting point of 350 deg.C or above is used for the nonflammable tape. A heat-resistant electric wire or a cable with extreme practicability is obtained according to this constitution.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to heat-resistant electric wires and cables thereof, and in particular to electrical insulation and heat deformation-resistant electric wires formed by coating a conductor surface with a specific liquid crystal polymer insulating layer. The present invention relates to practically desirable electric wires and cables that have excellent durability, chemical resistance, and flame retardancy, and have a high continuous use temperature.

[Conventional technology and its problems]

Conventionally, electric wires have been required to have a coating insulating layer that has high resistance to heat deformation, and has also been required to have a halogen-free coating layer that does not generate halogen-containing gas such as hydrogen halide upon thermal decomposition. As a coating resin that meets such requirements, the practicality of polyolefins, particularly crosslinked polyethylene, has been evaluated, and many proposals have been made regarding them. However, cross-linked polyethylene-coated wires formed by extruding and coating such polyethylene onto conductive wires are, for example, IEC
When conducting a heat deformation test with a load of 5 kg according to the standard, the heat deformation temperature is approximately 105°C, which means that it is thermally unstable at that measurement temperature, and the thermal deformation rate is approximately 60%. Since the heat resistance is poor, and the flame retardance (oxygen index) is also unsatisfactory, improvements are desired.

On the other hand, a polyetheretherketone thermoplastic resin has recently been developed and proposed as a wire coating resin that improves such low heat resistance. This resin is crystalline and has a high melting point of, for example, 334°C, but the glass transition point is about 1
When the temperature is 50°C and no inorganic filler is included,
Based on the ASTM method, the heat deformation temperature under a load of 1.8.6 kg/ci is only about 152°C. Therefore, at temperatures above the glass transition point, the heat deformation becomes large and the heat resistance strength is extremely reduced. There is a drawback.

In addition, as resins for covering electric wires that particularly improve heat resistance, in place of crystalline resins such as polyether ether ketone, for example, non-quality ether imi 1 to resins such as polyether imi 1 to resin have been proposed. Ta. This resin has a high heating deformation temperature and a high continuous use temperature, but electric wires and cables made by extruding and coating conductors with these heat-resistant resins to form an insulating layer have a higher temperature between molecules than crystalline resins. Since the attractive force and bonding energy are small, there is a drawback that crazing and cracking are likely to occur particularly in organic solvents.

Furthermore, methods have been proposed in which ceramic tape, metal tape, metal laminate tape, thermosetting resin tape, etc., for example, are spirally wrapped around the conductor in order to make the electric wire flame retardant or non-combustible. However, since there is no suitable adhesive for adhering the overlapping portions of the wound tape, it is not possible to form an integrated nonflammable tape layer, and this method has not been put to practical use.

In addition, polyethylene terephthalate 1, which is a thermoplastic resin,
There is also a proposal to use a film of - (PET) for the same purpose, but while PET resin has heat fusion properties, it is prone to hydrolysis due to its chemical structure, and the heat deformation temperature of PET resin is 120 ° C. However, it is not possible to provide electric wires with high heat resistance.

Accordingly, an object of the present invention is to provide an insulated wire having excellent heat deformation resistance, electrical insulation property, chemical resistance, and high flame retardancy, and a cable formed from the same.

[Means for solving problems]

The present inventors relate to a wire coating layer that achieves the above object,
In particular, as a result of repeated experimental research on many resin materials with a focus on insulation coating resin, we have found that electrical wires that are extremely desirable for practical use
Found the cable. In addition, in such a liquid crystal polymer coated insulated wire, when a separator layer is provided between the conductor and the polymer coating layer formed on its surface using a nonflammable tape or a heat-resistant, flame-retardant tape, an even better wire can be obtained. It turns out that it can be provided.

That is, the present invention... p,p'-biphenol r p-
A heat-resistant electric wire or cable formed by forming a wholly aromatic polyester liquid crystal polymer obtained by reacting hydroxybenzoic acid and terephthalic acid as an insulating coating layer on the surface of a conductor, and furthermore, a heat-resistant electric wire or cable made of a fully aromatic polyester liquid crystal polymer obtained by reacting hydroxybenzoic acid and terephthalic acid, and a liquid crystal polymer between the conductor and the insulating coating layer. An object of the present invention is to provide electric wires and cables which have a non-combustible or flame-retardant separator tape layer and are more practical.

In the electric wire of the present invention, the insulating layer formed on the conductor is composed of PDP'-biphenol as an alcohol component, terephthalic acid as an acid component, and P-hydroxybenzoic acid having both a carboxylic acid group and an alcohol group. A wholly aromatic polyester liquid crystal polymer obtained by subjecting a mixture to an esterification reaction, and in the present invention, wholly aromatic means that all components to be reacted are substantially aromatic compounds. Therefore, it is preferable that the carboxylic acid group and the hydroxyl group in each of these components are substantially equivalent, and therefore p, ρ'-biphenol and terephthalic acid are usually used in approximately equivalent amounts,
The amount of p-hydroxybenzoic acid added is appropriately selected depending on the desired physical properties of the coating layer, and is usually in the range of about 100 to 500% by weight based on the total weight of both components. Regarding the desired physical properties of the resulting liquid crystal polymer as a coating layer, a relatively large amount is used when heat resistance and orientation are important, and a relatively large amount is used when extrusion processability and low orientation are important. A small amount is selectively used. Further, in the present invention, each component subjected to the reaction may be substituted with, for example, an alkyl group or other organic group, and the polyester liquid crystal polymer of the present invention may be substituted with such substituted derivatives. The polymer itself can be modified to, for example, impart stretchability to the resin itself to improve processability or, if desired, to improve heat resistance. Thus, the polyester-based liquid crystal polymer of the present invention includes these modified liquid crystal polymers.

As the polyester liquid crystal polymer used in the present invention, various liquid crystal polymers provided by Nippon Petrochemicals can be conveniently used.

The fully aromatic polyester-based liquid crystal polymer used in the electric wire of the present invention has a melting point around 420°C, so its extrusion coating temperature is high, but it not only has an excellent heat deformation temperature and continuous use temperature, but also has a good The present invention provides a wire coating layer that has chemical resistance and flame retardancy and is highly desirable in practice.

Further, the present invention provides an electric wire and a cable thereof having even better heat resistance, in which a nonflammable separator layer is provided between the conductor and an insulating layer coated on the surface of the electric wire. Such a separator tape layer is usually used to weaken the adhesion of the covering layer to the conductor, and is particularly advantageous in the case of solidification. If opening properties are required without using such a tape layer, it is preferable to perform pipe drawing or semi-pipe drawing.

Separator layers conveniently used in the present invention include, for example, metal tapes and glass tapes.

Inorganic tapes such as glass mica tape and ceramic tape, thermosetting resin tapes such as polyimide, polybismaleimide triazine, polyamino bismaleimide, and polyamideimide, thermoplastic liquid crystal polymer tapes, and 3
Examples include thermoplastic resin tapes having a melting point or softening temperature of 50° C. or higher. These tapes are generally prepared to a thickness of 7=10 μm to 500 μm and are usually adhered preferably with a heat resistant adhesive, although for thermoplastic tapes a heat sealant is advantageously used. .

This separator tape can be used, for example, by overlapping the tape,
It can be wrapped around the conductor using commonly known winding methods such as lap wrapping or vertical winding, and especially when liquid crystal polymer tape is used, it can be wrapped around the conductor using tape winding such as lap winding or vertical winding. It is extremely convenient because it can be easily integrated with the insulating layer-forming polymer by thermal fusion.

The electric wire of the present invention can be coated by heating and extruding a polyester-based liquid crystal polymer onto the conductor surface, or it is also possible to form a coating layer by wrapping a film of the polymer and heat-treating it to fuse the polymerized parts. can.

Furthermore, the heat-resistant electric wire of the present invention produced in this way is made by bundling a plurality of wires together and wrapping them in a solid intervening layer made flame-retardant with, for example, metal hydroxide, and then covering the outside with metal hydroxide. By covering with a sheath layer made of acrylic rubber, nitrile rubber, hydrogenated nitrile rubber, urethane rubber, polyolefin elastomer, etc. made flame retardant with oxides, etc., cables with excellent flame retardancy and heat resistance can be easily manufactured. .

〔Example〕

Next, the present invention will be explained in more detail using specific examples.

The methods for measuring each of these performances are as follows.

(1) Heating distortion temperature = (℃) 18.6 according to the method specified in ASTM 0648
kg/cn? The load is applied to the sample and measured.

A practically desirable temperature is 180°C.

(2) Chemical resistance: Weight change, dimensional change, and mechanical strength change were measured using the immersion test method for various chemicals in accordance with ASTM D 543, and then dissolved.

Observe the appearance of swelling, cracks, etc.

(3) Electrical insulation: Performed according to ASTM D 257.

(4) Flame retardancy: Performed according to ASTM D 2863.

(5) Continuous operating temperature: UL 40,000 hours open time continuous operating temperature C) specified in UL 746B can be checked.

(6) Hydrolyzability: An electric wire with an insulating layer formed thereon is immersed in hot water at 90°C.
Apply a voltage of 60V. Defined by the number of short-circuit days (insulation resistance IR=OΩ) at that time.

(7) Self-adhesiveness: The peeling force between the separator tape and the extrusion-coated liquid crystal polymer is determined according to the tensile test of JIS C3005. Note that the tensile speed in this case is 50 mm/min.

In addition, qualitative evaluation from a practical standpoint is as follows.

◎...Excellent 0...Good △...Slightly poor ×...Poor Example 1 and Comparative Examples 1 to 3 Produced by reacting three types of PDP'-biphenol, p-hydroxybenzoic acid and terephthalic acid. The obtained polyester liquid crystal polymer (trade name: Xydar STR300, sold by Nippon Petrochemicals Co., Ltd.) was extruded and coated onto a conductive wire, and an electric wire was continuously manufactured over a long period of time.

For comparison, cross-linked polyethylene currently in use,
Insulating coating materials of polyetheretherketone resin and polyetherimide resin were similarly extruded continuously onto a conductive wire to produce a covered electric wire.

The heating deformation rate (heating deformation temperature) and chemical resistance of the coating layer of each of these extruded covered wires.

Various performances such as electrical insulation, flame retardance, and continuous use temperature were investigated. The results are summarized in Table 1 below.

=IJ- Table 1 [Extrusion coated wire] Example 1 Comparative example 1 2 3 (Temperature °C) ◎ ××x~Δ 0 Chemical resistance
◎ Δ ◎ × (with swelling)
(Cracked by solvent) Electrical insulation ◎
◎ ◎ ◎Continuous use temperature 220 9
0～100 220 250(℃) ○
× 0 ◎Flame retardant 43
17 37 47 (0□ index) Ox
△ 0 In addition, PE in the table is polyethylene, P
EEK stands for polyetheretherketone and PEI stands for polyetherimide.

From the above table, it can be seen that the liquid crystal polymer according to the present invention has various desirable physical properties required for an insulating layer coated on electric wires, and is far superior to conventional polymers that have some drawbacks in performance. I understand.

Example 2 Using the liquid crystal polymer film of Example 1, a conductive wire was wound into a film and heat fused to create a covered layer edge wire. Various physical properties were similarly investigated for the coating layer and for comparison, polyethylene terephthalate 1- (PET) and polyimide (PI) film-wound insulated wires that have been employed conventionally. The results are shown in the table below.

Table 2 [Film-wrapped insulated wire] Example 2 Comparative example 4 - 5 Physical properties Liquid crystal polymer PET PI hydrolyzability 0 (1 month) × (3 days or less) ◎ (3
(more than a month) Self-adhesiveness O (no peeling) O (no peeling) X (no adhesive strength) Chemical resistance ○
△ (O crack with 10% NaOH) Continuous use temperature 220 1.20
250('C) OX~Δ ◎Heating deformation rate 220 120 250(
Temperature °C) o × ~ △ ◎As mentioned above, the number of days in parentheses in the "Hydrolyzability" column in the table is the number of short circuit days, and the heating deformation temperature in the table is based on ASTM 06.
48], 8 and 6 kg.

Furthermore, although it does not appear in Tables 1 and 2 above, the wholly aromatic polyester liquid crystal polymer according to the present invention has A
According to STM D 543, e.g. motor oil,
After conducting an oil resistance test at 50°C for 1 month on various oils such as diesel oil, gasoline, and silicone oil, the tensile strength remained in the range of 95 to 105%, which was excellent. Shows oil resistance. In addition, organic solvents,
For example, ethyl alcohol, acetone, toluene, 1
, 1.1-1-The remaining percentages after being immersed in 1-1-lichlorethylene etc. at room temperature for one month are all in the range of 90 to 110%,
No cracks or crazing occurred, and excellent solvent resistance was exhibited.

Furthermore, there were no cracks or crazing in a water immersion test at 660 V and 90°C for 1 month, and the product had good hydrolysis resistance. , 10% sodium hydroxide, etc. at 50°C for 1 month), the residual elongation rate was 90 to 10.
At 5%, good acid resistance and alkali deterioration resistance were exhibited.

〔Effect of the invention〕

The electric wire and cable of the present invention have the following excellent effects.

1) The insulating coating layer has a high heat resistance deformation temperature, excellent chemical resistance and flame retardancy, and also has a high continuous use temperature of 200° C. or higher, and its application as a heat resistant electric wire is extremely wide.

2) Since it does not contain halogen elements, it does not generate hydrogen halide gas that is harmful to the human body when the cable is burned.

3) It has extremely high practical value as an insulating layer for extruded coated wires and film-wound coated wires.

Claims (4)

[Claims] 1. A heat-resistant electric wire or cable comprising a wholly aromatic polyester liquid crystal polymer obtained by reacting p, p'-biphenol, p-hydroxybenzoic acid, and terephthalic acid and forming an insulating coating layer on a conductor surface. 2. The electric wire or cable according to claim 1, further comprising a separator layer wrapped with a nonflammable tape between the conductor and the liquid crystal polymer insulation layer. 3. The electric wire or cable according to claim 2, wherein the nonflammable tape is a tape made of metal, glass, glass mica, or ceramic. 4. A patent claim in which the nonflammable tape is a tape made of polyimide, polybismaleimide triazine, polyamino bismaleimide, or polyamideimide curable resin, a tape made of thermoplastic aromatic polyester liquid crystal polymer, or a thermoplastic resin tape with a melting point of 350°C or higher Electric wires and cables listed in scope 2.